This invention relates to a flexible container for medical use. More specifically, the invention relates to a flexible container for medical solutions that may be used without the need for enclosing the flexible container in a separate overwrap container.
Disposable plastic containers have many advantages over previous medical storage containers, including resistance to breakage, light weight, occupy less space and are easier to handle. It is therefore often desireable to use disposable plastic bags rather than glass bottles or other containers for storing and dispensing certain medical solutions. The disposable plastic containers are most frequently made of polyvinyl chloride or ethylene vinyl acetate copolymer. Flexible bags are frequently formed by two rectangular sheets of plastic material flat-welded to each other on four sides. However, most flexible plastics such as the above described heat weldable plastic materials tend to have a significant degree of water vapor and gas permeability.
When disposable medical bags are formed, appropriate inlet and outlet ports are provided in the welded sides. The two sheets and the four welded sides define a reservoir whose volume is zero before it is filled under pressure through an inlet or port. After the reservoir is filled, the inlet is sealed and the plastic container is steam sterilized such as by an autoclave cycle. Inlet and outlet ports are typically pre-sterilized by radiation in order to minimize the duration of the steam sterilization cycle.
Since the medical solution in the containers may be stored in the pharmacy or hospital for extended periods, water vapor and gas permeation through the plastic material is a great concern. Thus for disposable plastic containers for medical use, a water vapor and/or gas impermeable overwrap container is needed to completely surround the flexible container. The overwrap is typically a high density polyethylene, a foil or other high barrier type material.
Recent concern about the disposal of medical waste such as by incineration has created a desire to limit the amount of waste material, such as the packaging, used in connection with medical products. Also it is preferred to continue using certain plastic materials for medical products.
U.S. Pat. Nos. 4,198,972 and 4,183,434 show one type of flexible storage bag wherein the access ports are hermetically enclosed by a protective closure that is integral with the bag material. However, the closure around the ports are peelably separable to expose the ports.
U.S. Pat. No. 3,520,471 discloses a sealed flexible container having sealed end compartments enveloping open fluid conduits. The conduits which are sealed during assembly of the end compartments can later be opened by pinch pressure.
U.S. Pat. No. 4,559,053 discloses a flexible container having a semi-rigid frame. The connecting tubes which traverse the frame are exposed and are not enclosed by the extending parts of the film sheets.
U.S. Pat. Nos. 4,479,989 and 4,596,573 disclose flexible containers having a separately formed rigid end port members. The end ports are exposed and are not enclosed by the extending parts of the film sheets.
Thus there is a desire and a need for a flexible solution container that can be conventionally manufactured and sterilized and yet maintain the initial formulation of the medical solution and the sterility of the access ports for extended periods of time without the need for a completely separate overwrap container.
There is a further need for a flexible container having an integral protective cover that is detachable so that the sterilized ports may be accessed. There is also a need for such a flexible container that minimizes the amount of waste material to be disposed, yet is still simple in design, reliable and inexpensive to manufacture.